<!doctype html>
<html>
<head>
    <meta charset="utf-8">
    <title>Globe - ECHARTS-GL</title>
    <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
    <meta name="apple-mobile-web-app-capable" content="yes"> <!-- Fullscreen Landscape on iOS -->
    <link rel="stylesheet" href="./common.css">
</head>
<body>
<div id="main"></div>
<script src="https://unpkg.com/d3-contour@1"></script>
<script src="https://unpkg.com/d3-geo@1"></script>
<script src="https://unpkg.com/d3-timer@1"></script>
<script src="../node_modules/echarts/dist/echarts.js"></script>
<script src="../node_modules/echarts/map/js/world.js"></script>
<script src="../dist/echarts-gl.js"></script>
<script src="lib/jquery.min.js"></script>
<script src="lib/stackBlur.js"></script>
<script src="lib/dat.gui.js"></script>
<script src="js/commonUI.js"></script>
<script>

    var config = {
        color: '#c0101a',
        levels: 1,
        intensity: 8,
        threshold: 0.01
    }

    var canvas = document.createElement('canvas');
    canvas.width = 4096;
    canvas.height = 2048;
    context = canvas.getContext("2d");

    context.lineWidth = 0.5;
    context.strokeStyle = config.color;
    context.fillStyle = config.color;
    context.shadowColor = config.color;

    var gui = new dat.GUI();

    image("asset/bathymetry_bw_composite_4k.jpg").then(function (image) {
        var m = image.height,
            n = image.width,
            values = new Array(n * m),
            contours = d3.contours().size([n, m]).smooth(true),
            projection = d3.geoIdentity().scale(canvas.width / n),
            path = d3.geoPath(projection, context);

        StackBlur.R(image, 5);

        for (var j = 0, k = 0; j < m; ++j) {
            for (var i = 0; i < n; ++i, ++k) {
                values[k] = image.data[(k << 2)] / 255;
            }
        }

        var option = {
            image: canvas
        }

        var results = [];

        function update(threshold, levels) {
            context.clearRect(0, 0, canvas.width, canvas.height);
            var thresholds = [];
            for (var i = 0; i < levels; i++) {
                thresholds.push((threshold + 1 / levels * i) % 1);
            }
            results = contours.thresholds(thresholds)(values);
            redraw();
        }

        function redraw() {
            results.forEach(function (d, idx) {
                context.beginPath();
                path(d);
                context.globalAlpha = 1;
                context.stroke();
                if (idx > config.levels / 5 * 3) {
                    context.globalAlpha = 0.01;
                    context.fill();
                }
            });
            option.onupdate();
        }

        d3.timer(function (t) {
            var threshold = (t % 10000) / 10000;
            update(threshold, 1);
        });

        initCharts(option);

        update(config.threshold, config.levels);

//   gui.add(config, 'levels', 0, 100).step(1).onFinishChange(function () {
//     update(config.threshold, config.levels);
//   });

//   gui.add(config, 'threshold', 0, 1.00).onFinishChange(function () {
//     update(config.threshold, config.levels);
//   });

        gui.addColor(config, 'color').onChange(function () {
            context.strokeStyle = context.fillStyle = context.shadowColor = config.color;
            redraw();
        });
    });

    function image(url) {
        return new Promise(function (resolve) {
            var image = new Image;
            image.src = url;
            image.onload = function () {
                var canvas = document.createElement("canvas");
                canvas.width = image.width / 4;
                canvas.height = image.height / 4;
                var context = canvas.getContext("2d");
                context.drawImage(image, 0, 0, canvas.width, canvas.height);
                resolve(context.getImageData(0, 0, canvas.width, canvas.height));
            };
        });
    }

    var chart;

    function initCharts(option) {
        chart = echarts.init(document.getElementById('main'));

        var contourChart = echarts.init(document.createElement('canvas'), null, {
            width: 4096,
            height: 2048
        });

        var img = new echarts.graphic.Image({
            style: {
                image: option.image,
                x: -1,
                y: -1,
                width: option.image.width + 2,
                height: option.image.height + 2
            }
        });
        contourChart.getZr().add(img);

        option.onupdate = function () {
            img.dirty();
        }

        // https://www.behance.net/gallery/50293671/T-GLOBEhttps://bl.ocks.org/mbostock/818053c76d79d4841790c332656bf9da

        chart.setOption({
            globe: {

                environment: 'asset/starfield.jpg',

                heightTexture: 'asset/bathymetry_bw_composite_4k.jpg',

                displacementScale: 0.05,
                displacementQuality: 'high',

                baseColor: '#111',

                shading: 'realistic',
                realisticMaterial: {
                    roughness: 0.2,
                    metalness: 0
                },

                postEffect: {
                    enable: true,
                    depthOfField: {
                        enable: true
                    },
                    bloom: {
                        intensity: 0.05
                    }
                },
                temporalSuperSampling: {
                    enable: true
                },
                light: {
                    ambient: {
                        intensity: 0
                    },
                    main: {
                        intensity: 0.1,
                        shadow: false
                    },
                    ambientCubemap: {
                        texture: 'asset/lake.hdr',
                        exposure: 1,
                        diffuseIntensity: 0.5,
                        specularIntensity: 2
                    }
                },
                viewControl: {
                    autoRotate: false
                },

                layers: [{
                    type: 'blend',
                    blendTo: 'emission',
                    texture: contourChart,
                    intensity: config.intensity
                }]
            }
        });

        window.addEventListener('resize', function () {
            chart.resize();
        });

        gui.add(config, 'intensity', 0, 10).onChange(function () {
            chart.setOption({
                globe: {
                    layers: [{
                        intensity: config.intensity
                    }]
                }
            })
        });
    }
</script>
</body>
</html>
